Citation

Schulze KH, Gerbaldi A, Chavet J. Transp. Res. Rec. 1977; 623: 1-10.

Copyright

(Copyright © 1977, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Because of various other factors involved in skidding accidents, friction numbers as measured under standardized conditions of test cannot be expected to give a clear-cut ranking to surfaces according to their safety to traffic under wet conditions. Nevertheless, the concept of standardized test conditions is inevitable from a pracitical point of view. Regression type analyses compare accident figures or rates with friction numbers (examples from the Netherlands, the F.R. of Germany, and France). The most striking evidence of the important role slipperiness can play in wet-road accidents in yielded, however, by reliable before-and-after studies (examples from Italy and Great Britain). The establishment of standard, guide or minimum friction numbers is mainly based or regression type analyses. From country to country such values are quite different in character and significance. The support highway authorities in decisions on maintenance and renewal work but only in Belgium, the Netherlands, and Switzerland they serve as an acceptance criterion for road works. Current practice is described. For the suppression of black spots in wet conditions the two approaches are systematic routine measuring campaigns and evaluations of the accident statistics, the latter preferably based on the propertion of wet-road accidents. Interdisciplinary work is necessary to elaborate proposals for remedial measures which will generally include factors other than slipperiness (e.g. Safety Operation No. 6 in France). Juridical aspects in skidding cover the contractor's liability, the liability of the highway administrations, and the personal liability of their civil servants. Despite of the great variety in legal conditions, some general remarks can be made.